Alcohol vs. marijuana in the brain

Every year my students ask the same question about alcohol and marijuana: which is more dangerous to consume? In truth, this is a difficult question to answer because the two drugs have quite different and complex actions in the brain. Also, it's difficult to define what "more dangerous" really means with regard to the brain, particularly as compared to the well-known consequences of the consumption of alcohol on the body. Furthermore, the long term effects of both drugs are often quite different from their short term effects. Also, as I emphasized in my last blog about the relationship of marijuana smoking to psychosis, relative danger depends importantly upon specific genetic vulnerabilities inherited from our parents. Therefore, I find that answering this perennial question is often analogous to comparing the proverbial apples and oranges. Recently however some advances in the research on both drugs have provided some additional insight into a partial answer, at least from the standpoint of the brain.

A recent publication in Proceedings of the National Academy of Sciences from the Scripps Research Institute in California investigated the effects of binge alcohol consumption upon the adolescent brain. Many recent studies have already demonstrated that adolescence is a time of increased vulnerability of the brain to chemical insults. Furthermore, to make this issue even more timely, binge alcohol consumption by teenagers is increasing. The neuroscientists at Scripps discovered that binge alcohol consumption is particularly injurious to a region of the brain called the hippocampus. The hippocampus plays a critical role in learning and memory. Within the hippocampus are a group of cells that continually produce new brain cells, called neurons, throughout our life. This process of cell renewal is called "neurogenesis;" whenever this process is impaired we have trouble forming new memories and we develop the symptoms of depression, to mention just two consequences.

The Scripps scientists discovered that eleven months of binge alcohol consumption that produced a blood alcohol level sufficient to be considered intoxicated decreased neurogenesis by more than fifty percent! Furthermore, the decrease in neurogenesis lasted for many weeks of abstinence. You might think that alcohol binging also caused more cells to die; actually, this did not happen. That old urban myth is simply not true. The only change observed was a decrease in the production of new neurons. The authors suggested that these changes might produce a long lasting vulnerability within the hippocampus that may well predispose these young adults to neurodegeneration later in life.

In contrast to the effects of alcohol, a series of publications during the past few years suggest that stimulating the brain's marijuana neurotransmitter system appears to have the exact opposite effects upon neurogenesis in the hippocampus of both young and old laboratory animals and humans, i.e. neurogenesis is increased by stimulation of our brain's marijuana receptors.

When we are elderly, our brain displays a dramatic decline in neurogenesis within the hippocampus. This decline may underlie age-associated memory impairments as well as depression. Research in my laboratory has demonstrated that stimulating the brain's marijuana receptors restores neurogenesis. Thus, later in life, marijuana might actually help your brain, rather than harm it.

Considered together, the results of these studies can teach us a lot about the role of our endogenous marijuana neurotransmitter system during our brain's ongoing process of repair and re-wiring as we mature. Binge alcohol consumption during the more vulnerable periods of our lives is clearly able to interfere with these critical neural processes and produce significant long-term negative consequences. In spite of many recent advances by laboratories around the world, much remains to be investigated regarding the effects of these two commonly consumed chemicals upon the brain. At least next year I'll have a better answer to my students' recurring question.

What about the LONG TERM effects of using marijuana,(since teens into their adult life, age ,almost 6o), especially someone who has anxiety and depression, which they are taking meds for. Not to mention meds they are taking for pain??

The long term effects of cannabis have been tough to study since a lot of legislation blocks such studies from being done on a large scale. That being said, cannabis saw a huge increase in usage among young people in the 1960's, yet there seems to be no reported epidemic of problems caused by cannabis use by people who have used it since way back then.

Another interesting thing is that the surge in cannabis use in the 60's saw no real change in the rate of schizophrenia in the United States, even though various sources have claimed that cannabis can cause schizophrenia and other mental disorders.

Cannabis has a weird relationship with anxiety and depression. One of the most commonly reported side effects of high THC cannabis is anxiety, and some studies have shown that chronic heavy use can cause depression. Oddly enough, small to moderate doses of cannabis have been shown in studies on lab animals to be an effective treatment for depression. Strains of cannabis high in the cannabanoid CBD have also shown themselves to be helpful for various forms of anxiety and war vets with PTSD have reported some pretty great results when using medical cannabis to treat their problems. It seems moderation and knowing what strain you're using is the key here, as all the problems seem to stem from heavy use and very potent recreational strains.

As far as pain goes, cannabis is remarkably effective at treating some types of pain. As an example, I have a friend who has suffered from migraines since his teens, and he tried medical cannabis for his pain after a long struggle with abuse and withdrawals of opiate based pain meds. The cannabis ended up working better for him than the opiates, and without the terrible addiction, side effects, and withdrawals. Many people have also reported it to be effective at treating nerve pain from conditions such as multiple sclerosis and I can personally say that it helped with my back pain from an old injury more than anything else I've tried.

I'm not touting cannabis as some sort of panacea or miracle cure, but the information on the medical properties of the plant and its safety are out there, and it could potentially help a lot of people if it was made more available to those who could benefit from it.

Now, anyone who reads this and thinks of trying cannabis, whether for recreational or medical purposes, needs to check their local laws and regulations before doing so. They also need to take the time to educate themselves on cannabis and the condition or problem that they're suffering from. Knowledge is an amazing thing, and it's never been easier to educate yourself than it is today, you just need to learn to sift through a lot of BS and misinformation to get to the real meat of the issues you're looking at.

Let's not forget that long term use of cannabis decreases the size of the right hippocampus associated with memory. Even if there are benefits of THC it also has alot of negative things to it aswell, as do most things. What i said has been proven so if anyone tries to argue against this you are wasting your time.